band reject filter design

Thread Starter

sarjan88

Joined Apr 23, 2011
1
Design a circuit using op-amp that will reject the 60kHz power line noise and also reject high signal frequency above 800Khz. The stop-band width around the 60kHz centre frequency is 10kHz. Use a cascade of 1st order high pass and 1st order low pass filter to implement this circuit. The voltage gain at passband frequencies is 10.

As mentioned in the title, can sum1 tell me this should be a band reject or band pass filter?
i try to construct a band reject filter but the result seem like not correct.

here is my circuit using multisim
http://i325.photobucket.com/albums/k392/sarjan123/circuit.jpg
here is the result using AC analysis in decibel
http://i325.photobucket.com/albums/k392/sarjan123/result.jpg
bode plot


can sum1 help me out of this?
thanks
 

Audioguru

Joined Dec 20, 2007
11,248
Your V3 battery is only 0V.
All opamps are biased at 0V and with the single positive supply they become rectifiers.
With your single +10V supply all opamps should be biased at +5V, not at 0V. Or use a double-polarity supply.
 
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